Hydrocracking catalyst and a diesel production process

ABSTRACT

The invention provides an amorphous hydrocracking catalyst for conversion of a hydrocarbon feed having a fraction above the diesel boiling range to diesel and a process using said catalyst. The catalyst includes Al 2 O 3 —SiO 2  support, a noble catalytically active metal which is active for hydrocracking of a hydrocarbon above the diesel boiling range and a transition metal oxide selected from group V, VI and VII.

FIELD OF THE INVENTION

[0001] The invention relates to a hydrocracking catalyst suitable forthe production of diesel boiling range hydrocarbons and to a dieselproduction process using said catalyst.

[0002] Background to the Invention

[0003] The applicant is aware that presently in order to produce dieselfrom a hydrocarbon feed including a fraction having a boiling point inexcess of the diesel boiling range by hydrocracking a high recirculationratio is required thereby leading to reduced viability of the productionof said diesel. The high recirculation ratio is necessitated, foramongst other reasons, by the relatively low conversions and yields tothe desired products

[0004] The applicant is further aware that diesel for commercial useshould preferably have good cold flow properties, a low cloud point, anda cetane number in excess of 40.

[0005] The applicant is also aware that existing hydrocracking catalystsused presently for the production of diesel from a hydrocarbon feedhaving a fraction having a boiling point above the diesel boiling rangeinclude commercially available amorphous Ni/W/Al₂O₃SiO₂ catalysts aswell as Ni/Mo/Al₂O₃SiO₂ catalysts which require a high recirculationratio as described above and amorphous Pt/Al₂O₃SiO₂ which is ahydrocracking and dewaxing catalyst which also requires a highrecirculation ratio as described above in order to produce said diesel.

[0006] The applicant is also aware of an article by S Rajagopal, J. A.Marzari and R Miranda entitled Silica-Alumina-Supported Mo OxideCatalysts: “Genesis and Demise of Brönsted-Lewis Acidity”, which articlewas published in the Journal of Catalysis 151, 192-203 (1995). Theentire article is incorporated in this specification by reference as ifspecifically reproduced here.

[0007] In the aforementioned article the authors summarise that theratio of Brönsted to Lewis acid sites concentration (B/L) increases withSiO₂ content in the support and reaches a maximum for SiO₂:Al₂O₃ of 3:1by weight. For alumina rich supports B/L increases continuously withMoO₃ loading because of the generation of new Brönsted acid sites anddecrease of Lewis acid sites, up to a theoretical maximum of 12 wt %MoO₃. The article does not propose the manufacture of a catalyst of thetype of this invention nor would the results set out in the article leada man skilled in the art to conclude that a catalyst in accordance withthis invention could be manufactured.

[0008] In this specification, unless the context clearly indicates tothe contrary, the term conversion is used to indicate the conversion ofthe hydrocarbon feed to reaction products on a single pass through thereactor i.e. without recycle of reactor bottoms.

[0009] Thus, after prolonged and laborious experimentation anddevelopment work on diesel production the applicant now proposes a newcatalyst and a new diesel production process in accordance with theinvention.

SUMMARY OF THE INVENTION

[0010] The invention provides an amorphous hydrocracking catalyst forconversion of at least a portion of a hydrocarbon feed having a fractionabove the diesel boiling range to diesel, said catalyst including:

[0011] a Al₂O₃—SiO₂ support;

[0012] a noble catalytically active metal which is active at least forthe hydrocracking of a hydrocarbon above the diesel boiling range; and

[0013] a transition metal oxide wherein the transition metal is selectedfrom Group V, Group VI and Group VII transition metals.

[0014] The ratio of SiO₂to Al₂O₃ in the support may be between 1:4 and4:1.

[0015] The ratio of SiO₂ to Al₂O₃ in the support may be between 1:2 and7:2.

[0016] The ratio of SiO₂to Al₂O₃in the support may be between 2:4 and7:2.

[0017] The ratio of SiO₂ to Al₂O₃ in the support may be about 3:1.

[0018] The catalytically active noble metal may be Pt, Pd, Ir, or Rh.

[0019] The catalytically active noble metal is typically Pt.

[0020] The catalytically active noble metal may be present at between0.1% to 5% of the weight of the catalyst.

[0021] The catalytically active noble metal is typically present atbetween 0.5% to 1.5% of the weight of the catalyst.

[0022] The catalytically active noble metal is usually about 1.2% of theweight of the catalyst.

[0023] The transition metal oxide is typically a Group Vi transitionmetal oxide, for example, MoO₃.

[0024] The transition metal oxide may be between about 0.5% and 15% ofthe catalyst weight.

[0025] The transition metal oxide may be between about 1.5% and 12% ofthe catalyst weight.

[0026] Typically the transition metal oxide is about 2% of the catalystweight.

[0027] In one embodiment the catalyst is Pt/MoO₃/Al₂O₃SiO₂ having about12 wt % Pt and about 2 wt % MoO₃, and a SiO₂ to Al₂O₃ weight ratio ofabout 3:1.

[0028] The catalyst is a non-sulphided catalyst.

[0029] According to a further aspect of the invention there is providedan amorphous hydrocracking catalyst for conversion of at least a portionof a hydrocarbon feed having a fraction above the diesel boiling rangeto diesel, said catalyst having an acidity of between 0.1 and 0.9 mmolNH₃/g catalyst.

[0030] Typically, said catalyst has an acidity of between 0.25 and 0.6mmol NH₃/g catalyst.

[0031] Typically, said catalyst has an acidity when freshly prepared of0.38 mmol NH₃/g catalyst

[0032] Typically, said catalyst has an acidity when used (spent) of 0.45mmol NH₃/g catalyst

[0033] The catalyst may have a Brönsted/Lewis ratio (B/L) of between 0.3and 1.2.

[0034] Typically, said catalyst may have a Brönsted/Lewis ratio of 0.44.

[0035] The applicant believes that the B/L ratio of the support of thecatalyst, which is substantially higher than some prior arthydrocracking catalysts, results in the catalyst of the inventionfavouring a tertiary to tertiary cracking mechanism, also called a TypeA cracking mechanism, which cracking mechanism is substantially fasterthan the Type B1 and B2 cracking mechanisms.

[0036] It is believed that a high B/L content on the amorphous supportis important as the alkene receives a proton from the support, thentransforms into a carbocaton.

[0037] Isomerization is an important step in the hydrocracking mechanismas a linear paraffin molecule has typically to be isomerized three timesbefore the dominant A-type hydrocracking takes place.

[0038] Over bifunctional catalysts, it has been found that type Ahydrocracking is by far the fastest reaction; 375 times faster than typeB1 and 1050 times faster than type B2 hydrocracking

[0039] The applicant further believes that the non-sulphided nature ofthe catalyst of the invention is advantageous in a hydrocarbonprocessing stream where sulphur levels are very low or absent, such as aFischer-Tropsch process in which there is typically no or little sulphurin the feedstream and thus sulphur removal is not provided for.

[0040] According to a further aspect of the invention there is provideda process for conversion of at least a portion of a hydrocarbon feedhaving a component above the diesel boiling range to diesel, saidprocess including contacting under conversion temperatures and pressuressaid hydrocarbon feed with a catalyst including:

[0041] a Al₂O₃SiO₂ support;

[0042] a noble catalytically active metal which is active at least forthe hydrocracking of a hydrocarbon above the diesel boiling range; and

[0043] a transition metal oxide wherein the transition metal is selectedfrom Group V, Group VI and Group VII transition metals.

[0044] The ratio of SiO₂ to Al₂O₃ in the support may be between 1:4 and4:1.

[0045] The ratio of SiO₂ to Al₂O₃ in the support may be between 1:2 and7:2.

[0046] The ratio of SiO₂to Al₂O₃in the support may be between 2:4 and7:2.

[0047] The ratio of SiO₂ to Al₂O₃ in the support may be about 3:1.

[0048] The catalytically active noble metal may be Pt, Pd. Ir, or Rh.

[0049] The catalytically active noble metal is typically Pt.

[0050] The catalytically active noble metal may be present at between0.1% to 5% of the weight of the catalyst.

[0051] The catalytically active noble metal is typically present atbetween 0.5% to 1.5% of the weight of the catalyst.

[0052] The catalytically active noble metal is usually about 1.2% of theweight of the catalyst.

[0053] The transition metal oxide may be any Group VI b (Group 6) oxide,typically MoO₃

[0054] The transition metal oxide may be between about 0.5% and 15% ofthe catalyst weight.

[0055] The transition metal oxide may be between about 1.5% and 12% ofthe catalyst weight.

[0056] Typically the transition metal oxide is about 2% of the catalystweight.

[0057] In one embodiment the catalyst is Pt/MoO₃/Al₂O₃SiO₂ having about1.2 wt % Pt and about 2 wt % MoO₃, and an SiO₂ to Al₂O₃ weight ratio ofabout 3:1.

[0058] The catalyst is a non-sulphided catalyst.

[0059] The process may be carried out at a temperature of between 250°C. and 450° C.

[0060] The process may be carried out at a temperature of between 330°C. and 390° C.

[0061] The process may be carried out at temperature of between about350° C. and 380° C.

[0062] Typically the process is carried out at between 360° C. to 370°,usually 370° C.

[0063] The process may be carried out a pressure of between 10 and 200Bar, although a typical range is between 15 and 70 Bar.

[0064] The process may be carried out at 70 Bar where a high diesel tonaphtha ratio of above 6 is required at a conversion rate of above 60%.

[0065] The process may be carried out at a pressure of about 70 Bar andat a temperature of about 370° C. to give a diesel to naphtha ratio ofabout 6.4 at a conversion of about 70%, said diesel having a cloud pointof about −19° C.

[0066] The process may be carried out without recycle of a bottomsfraction.

[0067] The process may be carried out with a recycle ratio of bottomsfraction from the reactor to fresh hydrocarbon feed of from 4:1 to 1:9(20%/-90% conversion)

[0068] The process may be carried out with a volumetric H₂ tohydrocarbon feed ratio of between 800:1 and 3000:1, typically 1000:1 to1500:1.

[0069] The process may be carried out with a weight hourly spacevelocity (whsv) of between 0.25 h⁻¹ and 1.5 h⁻¹, typically 0.5 h ⁻¹ and1 h⁻¹.

[0070] The diesel and naphtha products of the process may be produced ata ratio of at least 6:1, typically 6.4:1.

[0071] The conversion to diesel may be at least 60%, typically 70% andeven as high as 80%.

[0072] In one embodiment, the diesel to naphtha ratio is about 6.4:1 ata conversion to diesel of 70% when the process is carried out at 370° C.and a pressure of 70 Bar.

[0073] Typically the hydrocarbon feed is predominantly a wax feed, forexample a Fischer-Tropsch wax.

[0074] According to yet a further aspect of the invention, there isprovided a process for conversion of at least a portion of a hydrocarbonfeed having a component above the diesel boiling range to diesel, saidprocess including contacting under conversion temperatures and pressuressaid hydrocarbon feed with a conversion catalyst, wherein productfractions of the process include:

[0075] a naphtha fraction;

[0076] a diesel fraction; and

[0077] a bottoms fraction which predominantly contains hydrocarbonshaving a boiling range above the diesel boiling range;

[0078] wherein the diesel to naphtha ratio is at least 6 when theconversion of hydrocarbon feed is at least 60%.

[0079] The diesel to naphtha ratio may be between 6 and 7, typically 6.4at a conversion of 70% when the process is carried out at 370° C. and ata pressure of 70 Bar.

[0080] The process may include the recycling of the bottoms fractionwherein the recycle ratio of bottoms fraction to fresh hydrocarbon feedis less than 4:1, typically less than 3:7.

[0081] In one embodiment there is no recycling of the bottoms fraction.

[0082] The conversion catalyst may include:

[0083] a Al₂O₃—SiO₂ support;

[0084] a noble catalytically active metal which is active at least forthe hydrocracking of a hydrocarbon above the diesel boiling range; and

[0085] a transition metal oxide wherein the transition metal is selectedfrom Group V, Group VI and Group VII transition metals.

[0086] The ratio of SiO₂to Al₂O₃in the support may be between 1:4 and4:1.

[0087] The ratio of SiO₂to Al₂O₃ in the support may be between 1:2 and7:2.

[0088] The ratio of SiO₂to Al₂O₃in the support may be between 2:4 and7:2.

[0089] The ratio of SiO₂to Al₂O₃in the support may be about 3:1.

[0090] The catalytically active noble metal may be Pt, Pd, Ir, or Rh.

[0091] The catalytically active noble metal is typically Pt.

[0092] The catalytically active noble metal may be present at between0.1% to 5% of the weight of the catalyst.

[0093] The catalytically active noble metal is typically present atbetween 0.5% to 1.5% of the weight of the catalyst.

[0094] The catalytically active noble metal is usually about 1.2% of theweight of the catalyst.

[0095] The transition metal oxide may be any Group 6 oxide, typicallyMoO_(3.)

[0096] The transition metal oxide may be between about 0.5% and 15% ofthe catalyst weight.

[0097] The transition metal oxide may be between about 1.5% and 12% ofthe catalyst weight.

[0098] Typically the transition metal oxide is about 2% of the catalystweight.

[0099] In one embodiment the catalyst is Pt/MoO₃/Al₂O₃SiO₂ having about1.2 wt % Pt and about 2 wt % MoO₃, and a SiO₂ to Al₂O₃ weight ratio ofabout 3:1.

[0100] The catalyst is a non-sulphided catalyst.

[0101] The process may be carried out at a temperature of between 250°C. and 450° C.

[0102] The process may be carried out at a temperature of between 330°C. and 390° C.

[0103] The process may be carried out at temperature of between about350° C. and 380° C.

[0104] Typically the process is carried out at between 360° C. to 370°,usually 370° C.

[0105] The process may be carried out a pressure of between 10 and 200Bar, although a typical range is between 15 and 70 Bar.

[0106] The process may be carried out at 70 Bar where a high diesel tonaphtha ratio of above 6 is required at a conversion rate of above 60%.

[0107] The process may be carried out at a pressure of about 70 Bar andat a temperature of about 370° C. to give a diesel to naphtha ratio ofabout 6.4 at a conversion of about 70%, said diesel having a cloud pointof about −19° C.

[0108] The process may be carried out with a volumetric H₂ tohydrocarbon feed ratio of between 800:1 and 3000:1, typically 1000:1 to1500:1.

[0109] The process may be carried out with a weight hourly spacevelocity (whsv) of between 0.25 h⁻¹ and 1.5 h⁻¹, typically 0.5 h⁻¹ and 1h⁻¹.

[0110] The conversion to diesel may be at least 60%, typically 70% andeven as high as 80%.

[0111] Typically the hydrocarbon feed is predominantly a wax feed, forexample a Fischer-Tropsch wax.

[0112] The Fischer-Tropsch wax may be selected from a Group including

[0113] a primary FT reactor product;

[0114] wax A, or distillation fractions thereof;

[0115] wax B;

[0116] wax C

[0117] wherein waxes A, B and C have characteristics as set out in thetable below.

[0118] Wax Characteristics: Wax Type Congealing point (° C.) Substantialcarbon distribution A 83-103, typically 93  C₅-C₁₂₀ B  49-69, typically59 C₁₇-C₄₅ C  71-91, typically 81 C₃₀-C₈₅

[0119] The invention extends to a diesel produced by the process of theinvention, the diesel having a cetane number in excess of 40.

[0120] The diesel may have a cetane number between 65 and 75, typically70.

[0121] The diesel may have a cloud point below −19° C.

[0122] Typically the diesel has a cloud point below −25° C.

SPECIFIC DESCRIPTION OF THE INVENTION CATALYST EXAMPLE 1

[0123] A non-sulphided Pt/MoO₃/Al₂O₃—SiO₂ catalyst was prepared in whichthe support was amorphous. The particle size of the catalyst was ⅛″.

[0124] Catalyst Preparation.

[0125] 75% Degussa silica (300 grams), 25% Degussa alumina (100 grams)and HNO₃ 55% (100 ml) were introduced into a mixer. While mixing,distilled water was added drop wise until a stiff dough was obtained.The paste was kneaded for about 3 hours.

[0126] At the end of the reaction, the mixture was placed in an oven at120° C. for 10 hours in order to ensure proper drying, then pelletisedto 3000 and 6000 micrometers.

[0127] Following this, the support was calcined in air at 550° C. for 3hours.

[0128] 100 grams of the support was impregnated with 100 ml of(NH₄)₆Mo₇O₂₄.4H₂O (2.4525 grams) solution until a 2.2% MoO₃ content wasloaded. The mixture was calcined in air at 400° C. for 4 hours. Then 100grams of the mixture was impregnated with 100 ml of [Pt(NH₃)₄](NO₃)₂(1.9846 grams) solution until a 1.2% Pt content was loaded; then thecatalyst was calcined at 400° C. in air for 4 hours in order toeliminate all the NH₃ and to obtain the desired oxide MoO₃.

[0129] Reduction of the Catalyst

[0130] The catalyst was reduced in-situ in a fixed bed at 350° C. for 8hours with a hydrogen flow rate of 1.7 l/min in order to reduce theplatinum.

[0131] Catalyst Testing Apparatus

[0132] The catalyst testing was carried out in a fixed bed reactoroperating in down flow mode.

[0133] Other Apparatus and Techniques Used for Catalyst Characterization

[0134] BET Surface Area Measurements and Data

[0135] A Gemini micromeritics surface area machine was used. BET data ofthe catalyst was obtained. Catalyst characteristics are summarized intable A below. TABLE A Catalyst Characteristics A B C D E F G HPt/MoO₃/Al₂O₃—SiO₂ 1.2% Pt 65.1% SiO₂ 233 0.55 0.38 100 0.44 2.2% MoO₃19% Al₂O₃

[0136] Inductive Couple Plasma (ICP)

[0137] The amorphous support (Al₂O₃—SiO₂) was impregnated with a metaloxide (MoO₃) and a noble metal (Pt) and metal loadings were ascertainedby means of ICP.

[0138] The analyses were performed by AARL. ICP data forPt/MoO₃/Al₂O₃—SiO₂ was obtained. The results are given in table B below.

[0139] Table B: Percentage of Metal Loading on the Al₂O₃—SiO₃ TABLE BPercentage of metal loading on the Al₂O₃—SiO₃ Percentage of Metalloading Sample % added % found Pt/MoO₃/Al₂O₃—SiO₂ 1.3% Pt/ 1.2% Pt/ 2.3%MoO₃ 2.2% MoO₃

[0140] X-Ray Diffraction (XRD)

[0141] A Siemens D500 X-ray Powder Diffractometer was used to determinethe crystallinity of the catalyst and the catalyst was found to beclassifiable as amorphous.

[0142] Temperature Program Reduction (TPR)

[0143] A Micromeritics TPR 2900 analyzer was used. The catalyst wasreduced at 350° C.

[0144] Temperature Program Desorption (TPD) A Micromeritics TPD 2900NH₃analyzer was used for the determination of the catalyst acidity.

[0145] Catalyst Use

[0146] Tests to convert a Fischer-Tropsch reaction product wax to dieseland naphtha using the catalyst described above were performed at 370° C.in a fixed bed reactor without recycle.

[0147] Tests were also conducted to convert a Fischer-Tropsch reactionproduct to diesel and naphtha using the prior art Ni-W or Ni-Mocatalysts at 370° C. in a fixed bed reactor without recycle.

[0148] The results showed that the catalyst of the invention gavesuperior results of a diesel to naphtha ratio of 6.4:1 and a conversion(C₂₃₊ converted in product) of 70%, the diesel having an acceptablecloud point of about

[0149] −19° C.

[0150] The catalyst was also found not to have decreased in activity orperformance after 190 days of constant use whereas the prior artcatalysts are known to have a gradual decrease in activity from thefirst day of use until the catalyst must be replaced.

PROCESS EXAMPLE 1

[0151] An amorphous catalyst having the properties as set out in tables1 and 2 below and originally designed for the conversion of waxes tolube oils was prepared and used in a hydrocracking process to convert aFischer-Tropsch wax C to diesel. Wax C has a congealing point of 81° C.and a substantial carbon distribution of C₃₀ to C₈₅, as shown in thetable above. TABLE 1 Catalyst Characteristics A B C D E F G HPt/MoO₃/Al₂O₃— 1.2% Pt 65.1% SiO₂ 219 0.55 0.38 100 0.44 SiO₂ 2.2% MoO₃19% Al₂O₃

[0152] TABLE 2 Percentage of metal loading on the Al₂O₃—SiO₃ Percentageof Metal loaded Sample % added % found Pt/MoO₃/Al₂O₃—SiO₂ 1.3% Pt/ 1.2%Pt/ 2.3% MoO₃ 2.2% MoO₃

[0153] Temperature Program Reduction (TPR)

[0154] A Micromeritics TPR 2900 analyzer was used. The catalyst wasreduced at 350° C.

[0155] Temperature Program Desorption (TPD)

[0156] A Micromeritics TPD 2900 NH₃ analyser was used for thedetermination of the catalyst acidity.

[0157] Gas Chromatography (GC)

[0158] A GC was used to identify and to determine the carbon numberdistribution of the products. The analyses were performed byInstrumental Techniques laboratory.

[0159] Nuclear Magnetic Resonance (NMR)

[0160] A Varian Unity Inova 400 mHz NMR was used to determine the cetanenumber of the diesel fraction.

[0161] Catalyst Use

[0162] Tests to convert a Fischer-Tropsch wax having a liquid point of80° C. (wax C) to diesel were performed under a variety of conditions.The tests were conducted at pressures of 35 bar, 50 bar and 70 bar.

[0163] A summary of reactions performed is given in tables 3, 4 and 5.

[0164] Reactions were also performed with hydrocracked bottoms (HB)“>370° C.” from wax C (HB) as feedstock. A summary of the experimentsperformed using HB as feedstock is shown in table 6.

[0165] The diesel fraction produced 170°-370° C. during the experimentswere fractionated according to the true boiling point (TBP) while thespecification requires a diesel cut 170°-370° C. according to the ASTMD-86.

[0166] The diesel fraction of 170°-370° C. in TBP corresponds almost to190°-390° C. in ASTM-D86; therefore all flash points values resultedfrom the test runs were too high as the initial boiling point of thediesel were shifted by almost 20° C.

[0167] Wax C Conversion Over Pt/MoO₃/Al₂O₃—SiO₂ Catalyst

[0168] Wax C at a flow rate of 0.9-1.9 ml/min and H₂ at a flow rate of1.4-2.6 Nl/min were passed through Pt/MoO₃/Al₂O₃—SiO₂ catalyst (96.2 g)in the reactor.

[0169] Separate runs were carded out at various pressures (35 bar, 50bar and 70 bar) and various temperatures (360° C., 365° C. and 370° C.).

[0170] The results obtained after 3-4 days run at each temperature andpressure are shown in tables 3, 4 and 5. TABLE 3 The effect oftemperature on diesel selectivity and diesel properties at 50 bar, whsvof 0.5 h⁻¹ and H₂/wax of 1400. Run Specifications R 08 R 09 R 10Pressure (bar) 50 50 50 Temperature 370 365 360 (° C.) Whsv (h⁻¹) 0.50.5 0.5 H₂:wax 1432 1427 1467 Conversion_(D) (%) 84.4 78.9 58 S_(C1-C4)(%) 4.3 4.5 2.3 S_(C5-C9) (%) 21.5 20.7 16.4 S_(C10-C22) (%) 74.2 74.881.3 Y_(C1-C4) (%) 3.6 3.6 1.3 Y_(C5-C9) (%) 18.1 16.3 9.5 Y_(C10-C22)(%) 62.6 59 47.2 Residue (%) 15.6 21.1 42 Diesel/naphtha 3.5 3.6 5Diesel Properties iP/nP in C₁₀-C₂₂ 7.7 6.4 7.3 Cloud point (° C.) (−19°C.) max −25 −9 −3 Flash point (° C.) 57 min 84 84 78 Viscosity @ 2.0 <cSt < 5.3 2.6 2.7 3.2 40° C. Density @ 20° C. 0.766 g/cm³ 0.775 0.7770.781 Cetane number 70 min 71 72 73

[0171] Conversion_(D) (%)=(C₂₃₊ in fresh feed−C₂₃₊ in product)/C₂₃₊ infresh feed*100 from Carbon Number Distribution (CND)

[0172] S_(C10-C22) (%)=Diesel selectivity calculated as: (C₁₀-C₂₂ inproduct−C₁₀-C₂₂ in fresh feed)/(C₁-C₂₂ in product−C₁-C₂₂ in freshfeed)*100

[0173] Y_(C10-C22) (%)=Diesel yield calculated as:conversion_(D)*S_(C10-C22)

[0174] Conversion of Wax C at 50 Bar

[0175] As regards the quality of the products, the diesel fraction(C₁₀₋₂₂) produced presents excellent properties. An average ratioiC₁₀₋₂₂/nC₁₀₋₂₂ of 7/1 has been obtained. This high ratio explains thecloud point of −25° C. A diesel cetane number of 71 was found. TABLE 4Effect of temperature on diesel selectivity and diesel properties at 35bar, whsv of 0.5 h⁻¹ and H₂/wax of 1400 Run R 11 R 12 R 13 CatalystPt/Mo/Al—Si Pt/Mo/Al—Si Pt/Mo/Al—Si Pressure (bar) 35 35 35 Temperature(° C.) 360 365 370 Whsv (h⁻¹) 0.5 0.5 0.5 H₂:wax 1353 1452 1507Conversion_(D) (%) 72.8 85.5 95.2 Y_(C1-C4) (%) 1.0 3.7 2.0 Y_(C5-C9)(%) 14.6 19.7 29.3 Y_(C10-C22) (%) 57.3 62.2 64.0 Residue (%) 27.1 14.44.7 Diesel/naphtha 3.9 3.2 2.2 Diesel Properties iP/Np in C₁₀-C₂₂ 4.87.9 6 Cloud point (° C.) −29 −34 −39 CFPP (° C.) −34 −39 <−39 Flashpoint (° C.) 88 80 75 Viscosity @ 40° C. 2.5 2.7 2.2 Density @ 20° C.0.776 0.777 0.771 Cetane number 72 73 69

[0176] Conversion of Wax C at 370° C.

[0177] From table 5 the following points may be observed:

[0178] It was found that by lowering the pressure from 70 bar to 35 barthe

[0179] conversion increases

[0180] cold properties improve i.e. cloud point at 70 bar was −6° C.decreasing to −39° C. at 35 bar as can be seen from table 5.

[0181] The Cetane number, which measures the ignition quality of adiesel fuel, remained high and almost unchanged at low pressure. Thiscan be explained by the insignificant aromatic content in the diesel(below 1%).

[0182] Table 5: The Effect of Pressure on Diesel Selectivity and DieselProperties at 370° C., Whsv of 0.5 h⁻¹ and H₂/Wax of 1400. TABLE 5 Theeffect of pressure on diesel selectivity and diesel properties at 370°C., whsv of 0.5 h⁻¹ and H₂/wax of 1400. Run R 07 R 08 R 13 Pressure(bar) 70 50 35 Temperature (° C.) 370 370 370 Whsv (h⁻¹) 0.5 0.5 0.5H₂:wax 1327 1432 1507 Conversion_(D) (%) 48.7 84.4 95.2 Y_(C1-C4) (%)2.6 3.6 2.0 Y_(C5-C9) (%) 8.2 18.1 29.3 Y_(C10-C22) (%) 37.8 62.6 64.0Residue (%) 51.3 15.6 4.7 Diesel/naphtha 4.6 3.5 2.2 Diesel PropertiesiP/nP in C₁₀-C₂₂ 4.6 7.7 6 Cloud point (° C.) −6 −25 −39 CFPP (° C.)<−39 Flash point (° C.) 86 84 75 Viscosity @ 40° C. 2.7 2.6 2.2 Density@ 20° C. 0.777 0.775 0.771 Cetane number 72 71 69

[0183] Conversion of Hydrocracked Bottoms (“>370° C.”) Over aPt/MoO₃/Al₂O₃—SiO₂ Catalyst.

[0184] A study was also undertaken in which hydrocracked bottoms (HB,“>370° C.”) from wax C was used as feedstock. The purpose of this was toassess the product yielded and its quality.

[0185] Feed at a rate of 0.9-1.9 ml/min and H₂ at a flow rate of 1.4-2.6Nl/min were passed through a Pt/MoO₃/Al₂O₃—SiO₂ catalyst (96.2 g) bed inthe reactor.

[0186] Reactions were performed at two different temperatures, keepingother parameters constant. The results of the runs carried out attemperatures of 350° C. and 340° C., a pressure of 35 bar, a whsv of 0.5h⁻¹ and a H₂/wax of 1200 are shown in table 6.

[0187] Table 6: The Effect of the Hydrocracked Wax C Bottoms(Material>370 C) on Diesel Selectivity and Diesel Properties. TABLE 6The effect of the hydrocracked Wax C bottoms (material >370° C.) ondiesel selectivity and diesel properties. Run R 15 R 16 Pressure (bar)35 35 Temperature (° C.) 350 340 Whsv (h⁻¹) 0.53 0.55 H₂:wax 1215 1209Conversion_(D) (%) 93.7 54.8 Y_(C1-C4) (%) 2.7 1.1 Y_(C5-C9) (%) 15.69.2 Y_(C10-C22) (%) 75.5 44.5 Residue (%) 6.3 45.3 Diesel/naphtha 5 5Diesel Properties iP/nP in C₁₀-C₂₂ 7.8 6.2 Cloud point (° C.) −21 −28CFPP (° C.) −38 Flash point (° C.) 89 97 Viscosity @ 40° C. 2.75 3.16Density @ 20° C. 0.775 0.802 Cetane number 70 72

[0188] Conversion of Hydrocracked Bottoms Wax C (bp>370° C.) Using thePt/Mo Silica-Alumina Catalyst

[0189] The reactor temperature was set to 350° C. and was then reducedto 340° C. to avoid an overcracking of the hydrocracked wax C feedstockas it contains significant amount of iso-paraffins.

[0190] It can be noticed that at a conversion of 93.7% as well as 54.8%excellent cold properties have been obtained in both runs (−21° C. &−28° C.) combined with high cetane number (70 & 72). The effect ofconversion on cloud point was out of correlation i.e. at 93.7%conversion, it is expected a cloud point much lower than at 54.8%conversion. The explanation could be that molecular rearrangements inthe iso-paraffins structures might happen. Overcracking of the highlybranched iso-paraffins might affect the diesel cold properties.

PROCESS EXAMPLE 2

[0191] An amorphous catalyst having the properties as set out in tables1 and 2 of Process Example 1 was prepared and used in a hydrocrackingprocess to convert a Fischer-Tropsch wax known as Wax A to diesel. Wax Ahas a congealing point of 91° C. and a substantial carbon distributionof C₅ to C₁₂₀.

[0192] The amorphous non-sulphided, Pt/MoO₃/Al₂O₃—SiO₂ was used tohydrocrack Wax A with the objective to evaluate the catalyst forhydroisomerisation of waxes to lube base oils.

[0193] Surprisingly, the catalyst showed a good activity and a goodselectivity towards diesel. The activity of the catalyst was furthertested using the full range Fischer-Tropsch wax as feedstock.

[0194] Catalyst Use

[0195] Reactions to convert Wax A to diesel were performed under avariety of conditions. A pressure range of 35 bar, 50 bar and 70 bar, atemperature range of 365° C., 370° C. and 380° C., a weight hourly spacevelocity (whsv) of 0.5 h⁻¹, and a H₂/wax range of 1000, 1200 and 1300were covered in the study.

[0196] A summary of reactions performed is given in table 7.

[0197] Typical experimental details are given below.

[0198] Wax a Conversion Using the Pt/MoO₃/Al₂O₃—SiO₂ Catalyst

[0199] Wax A at a flow rate of 0.9-1.9 ml/min and H₂ at a flow rate of1.4-2.6 Nl/min was passed through Pt/MoO₃/Al₂O₃—SiO₂ catalyst (96.2 g)in the reactor.

[0200] Table 7: The Effect of Temperature on Diesel Selectivity andDiesel Properties at 70 Bar and Whsv of 0.5 h⁻¹ TABLE 7 The effect oftemperature on diesel selectivity and diesel properties at 70 bar andwhsv of 0.5 h⁻¹ Run R 27 R 28 Pressure (bar) 70 70 Temperature © 370 380WHSV (h⁻¹) 0.5 0.5 H₂:wax 1221 1242 Conversion (%) 70.1 79.5 Y_(C1-C4)(%) 1.2 1.3 Y_(C5-C9) (%) 9.3 18.8 Y_(C10-C22) (%) 59.6 59.4 Residue (%)29.9 20.5 Diesel/naphtha 6.4 3.2 Diesel Properties iP/nP in C₁₀-C₂₂ 3.94.1 Cloud point (° C.) −19 −20 Cetane number 70 69

PROCESS EXAMPLE 3

[0201] An amorphous non-sulphided catalyst having the properties as setout in tables 1 and 2 of Example 1, Pt/MoO₃/Al₂O₃—SiO₂, was used toconvert Wax B with the objective to evaluate the catalyst forhydroisomerisation of waxes to lube base oils. Surprisingly the catalystshowed a good activity and a good selectivity towards diesel. Wax B hasa congealing point of 59° C. and a substantial carbon distribution ofC₁₇ to C₄₅.

[0202] It was found, to the surprise of the applicant, that the preparedPt/MoO₃/Al₂O₃

[0203] —SiO₂ catalyst produces an excellent diesel comparable to thediesel quality obtained by hydrocracking Fischer-Tropsch (FT) waxesusing other commercially available amorphous hydrocracking catalysts.

[0204] Catalyst Use

[0205] Wax B was converted to diesel under a variety of conditions. Apressure range of 15 bar, 35 bar, 50 bar and 70 bar, a temperature rangeof 350° C. to 380° C., a weight hourly space velocity (whsv) range of0.5 h⁻¹ and a H₂/wax range of 1000, 1200 and 3000 were tested with theabove catalyst and the reactions performed are given in table 8.

[0206] The test work was performed in a bench scale fixed bed reactor.

[0207] Wax B Conversion Over Pt/MoO₃/Al₂O₃—SiO₂

[0208] Wax B at a flow rate of 0.054-0.114 l/h, H₂ at a flow rate of84-156 Nl/h was passed over the Pt/MoO₃/Al₂O₃—SiO₂ catalyst (96.2 g) inthe reactor.

[0209] Reactions were carded out at various pressures (15 bar, 35 bar,50 bar and 70 bar), various temperatures (350° C., 360° C., 365° C.,370° C. & 380° C.), whsv (0.5 h⁻¹) and various H₂/wax ratios (1000, 1200and 3000). The results obtained after stabilising the reactor for 3-4days at given temperature and pressure are shown in table 8.

[0210] Table 8: The Effect of Temperature on Diesel Selectivity andDiesel Properties at 35 Bar, a H₂/Wax Ratio of 1200 and Whsv of 0.5 h⁻¹TABLE 8 The effect of temperature on diesel selectivity and dieselproperties at 35 bar, a H₂/wax ratio of 1200 and whsv of 0.5 h⁻¹ Run R40 R 37 R 38 Pressure (bar) 35 35 35 Temperature (° C.) 350 360 365 WHSV(h⁻¹) 0.5 0.5 0.5 H₂:wax 1215 1238 1302 Conversion (%) 16.6 69.0 86.4Y_(C1-C4) (%) 0.3 0.8 1.8 Y_(C5-C9) (%) 1.6 15.2 21.2 Y_(C10-C22) (%)14.6 53 63.3 Residue (%) 83.4 31 13.6 Diesel/naphtha 8.9 3.5 3.0 DieselProperties iP/nP in C₁₀-C₂₂ 3.3 4.6 5.3 Cloud point (° C.) −9 −18 −17CFPP (° C.) −20 −25 Cetane number 75 71 70

1. An amorphous hydrocracking catalyst for conversion of at least aportion of a hydrocarbon feed having a fraction above the diesel boilingrange to diesel, said catalyst having a Brönsted/Lewis ratio (B/L) ofbetween 0.3 and 0.5.
 2. A catalyst as claimed in claim 1 wherein thecatalyst has an acidity of between 0.1 and 0.6 mmol NH₃/g catalyst.
 3. Acatalyst as claimed in claim 1 or claim 2 wherein the catalyst has anacidity of between 0.25 and 0.6 mmol NH₃/g catalyst.
 4. A catalyst asclaimed in any one of claims 1 to 3 wherein the catalyst has an aciditywhen freshly prepared of 0.38 mmol NH₃/g catalyst and has an aciditywhen used (spent) of 0.45 mmol NH₃/g catalyst.
 5. A catalyst as claimedin any one of the preceding claims wherein the catalyst has aBrönsted/Lewis ratio of 0.44.
 6. An amorphous hydrocracking catalyst forconversion of at least a portion of a hydrocarbon feed having a fractionabove the diesel boiling range to diesel, said catalyst including: aAl₂O₃—SiO₂ support; a noble catalytically active metal which is activeat least for the hydrocracking of a hydrocarbon above the diesel boilingrange; and a transition metal oxide wherein the transition metal isselected from Group V, Group VI and Group VII transition metals.
 7. Acatalyst as claimed in claim 6 wherein the ratio of SiO₂ to Al₂O₃ in thesupport is between 1:4 and 4:1.
 8. A catalyst as claimed in claim 6 orclaim 7 wherein the catalytically active noble metal is Pt, Pd, Ir, orRh.
 9. A catalyst as claimed in any one of claims 6 to 8 wherein thecatalytically active noble metal is present at between 0.1% to 5% of theweight of the catalyst.
 10. A catalyst as claimed in any one of claims 6to 9 wherein the transition metal oxide is typically a Group VItransition metal oxide.
 11. A catalyst as claimed in any one of claims 6to 10 wherein the transition metal oxide is MoO₃.
 12. A catalyst asclaimed in any one of claims 6 to 11 wherein the transition metal oxideis between about 0.5% and 15% of the catalyst weight.
 13. A catalyst asclaimed in any one of claims 6 to 12 wherein the ratio of SiO₂ to Al₂O₃in the support is between 1:2 and 7:2.
 14. A catalyst as claimed inclaim 13 wherein the ratio of SiO₂ to Al₂O₃ in the support is between2:4 and 7:2.
 15. A catalyst as claimed in claim 14 wherein the ratio ofSiO₂ to Al₂O₃ in the support is about 3:1.
 16. A catalyst as claimed inany one of claims 6 to 15 wherein the catalytically active noble metalis Pt.
 17. A catalyst as claimed in claim 16 wherein the catalyticallyactive noble metal is present at between 0.5% to 1.5% of the weight ofthe catalyst.
 18. A catalyst as claimed in claim 17 wherein thecatalytically active noble metal is about 1.2% of the weight of thecatalyst.
 19. A catalyst as claimed in any one of claims 6 to 17 whereinthe transition metal oxide is between about 1.5% and about 12% of thecatalyst weight.
 20. A catalyst as claimed in claim 19 wherein thetransition metal oxide is about 2% of the catalyst weight.
 21. Acatalyst as claimed in any one of claims 6 to 20 wherein the catalyst isa non-sulphided catalyst.
 22. An amorphous hydrocracking catalyst forconversion of at least a portion of a hydrocarbon feed having a fractionabove the diesel boiling range to diesel, wherein the catalyst isPt/MoO₃/Al₂O₃SiO₂ having about 1.2 wt % Pt and about 2 wt % MoO₃, and aSiO₂ to Al₂O₃ weight ratio of about 3:1.
 23. A process for conversion ofat least a portion of a hydrocarbon feed having a component above thediesel boiling range to diesel, said process including contacting underconversion temperatures and pressures said hydrocarbon feed with acatalyst including: a Al₂O₃—SiO₂ support; a noble catalytically activemetal which is active at least for the hydrocracking of a hydrocarbonabove the diesel boiling range; and a transition metal oxide wherein thetransition metal is selected from Group V, Group VI and Group VIItransition metals.
 24. A process as claimed in claim 23 wherein theprocess is carried out at a temperature of between 250° C. and 450° C.25. A process as claimed in claim 24 wherein the process is carried outat a temperature of between 330° C. and 390° C.
 26. A process as claimedin any one of claims 23 to 25 wherein the process is carried out apressure of between 10 and 200 Bar.
 27. A process as claimed in claim 26wherein the process is carried out at 70 Bar where a high diesel tonaphtha ratio of above 6 is required at a conversion rate of above 60%.28. A process as claimed in any one of claims 23 to 27 wherein theprocess is carried out at a pressure of about 70 Bar and at atemperature of about 370° C. to give a diesel to naphtha ratio of about6.4 at a conversion of about 70%, said diesel having a cloud point ofabout −19° C.
 29. A process as claimed in any one of claims 23 to 28wherein the process is carried out without recycle of a bottomsfraction.
 30. A process as claimed in any one of claims 23 to 28 whereinthe process is carried out with a recycle ratio of a bottoms fractionfrom the reactor to fresh hydrocarbon feed of from 4:1 to 1:9.
 31. Aprocess as claimed in any one of claims 23 to 30 wherein the process iscarried out with a volumetric H₂ to hydrocarbon feed-ratio of between800:1 and 3000:1.
 32. A process as claimed in claim 31 wherein theprocess is carried out with a volumetric H₂ to hydrocarbon feed ratio ofbetween 1000:1 and 1500:1.
 33. A process as claimed in any one of claims23 to 32 wherein the process is carried out with a weight hourly spacevelocity (whsv) of between 0.25 h⁻¹ and 1.5 h⁻¹.
 34. A process asclaimed in claim 33 wherein the process is carried out with a weighthourly space velocity (whsv) of between 0.5 h⁻¹ and 1 h⁻¹.
 35. A processas claimed in any one of claims 23 to 34 wherein the hydrocarbon feed ispredominantly a wax feed, for example a Fischer-Tropsch wax.
 36. Aprocess as claimed in any one of claims 23 to 35 wherein the catalyst isa non-sulphided catalyst.
 37. A process as claimed in any one of claims23 to 36 wherein the catalyst is Pt/MoO₃/Al₂O₃SiO₂ having about 1.2 wt %Pt and about 2 wt % MoO₃, and an SiO₂ to Al₂O₃ weight ratio of about3:1.
 38. A process for conversion of at least a portion of a hydrocarbonfeed having a component above the diesel boiling range to diesel, saidprocess including contacting under conversion temperatures and pressuressaid hydrocarbon feed with a conversion catalyst, wherein productfractions of the process include: a naphtha fraction; a diesel fraction;and a bottoms fraction which predominantly contains hydrocarbons havinga boiling range above the diesel boiling range; wherein the diesel tonaphtha ratio is at least 6 when the conversion of hydrocarbon feed isat least 60%.
 39. A process as claimed in claim 38 wherein the diesel tonaphtha ratio is 6.4 at a conversion of 70% when the process is carriedout at 370° C. and at a pressure of 70 Bar.
 40. A process as claimed inclaim 38 or claim 39 wherein the process includes the recycling of thebottoms fraction wherein the recycle ratio of bottoms fraction to freshhydrocarbon feed is less than 4:1.
 41. A process as claimed in claim 38or claim 39 wherein the process includes the recycling of the bottomsfraction wherein the recycle ratio of bottoms fraction to freshhydrocarbon feed is less than 3:7.
 42. A process as claimed in claim 38or claim 39 wherein the there is no recycling of the bottoms fraction.43. A process as claimed in any one of claims 38 to 42 wherein theprocess is carried out at a temperature of between 250° C. and 450° C.44. A process as claimed in any one of claims 38 to 43 wherein theprocess is carried out a pressure of between 10 and 200 Bar.
 45. Aprocess as claimed in claim 44 wherein the process is carried out at 70Bar where a high diesel to naphtha ratio of above 6 is required at aconversion rate of above 60%.
 46. A process as claimed in claim 45wherein the process is carried out at a pressure of about 70 Bar and ata temperature of about 370° C. to give a diesel to naphtha ratio ofabout 6.4 at a conversion of about 70%, said diesel having a cloud pointof about −19° C.
 47. A process as claimed in any one of claims 38 to 46wherein the process is carried out with a volumetric H₂ to hydrocarbonfeed ratio of between 800:1 and 3000:1.
 48. A process as claimed inclaim 47 wherein the process is carried out with a volumetric H₂ tohydrocarbon feed ratio of between 1000:1 and 1500:1.
 49. A process asclaimed in any one of claims 38 to 48 wherein the process is carried outwith a weight hourly space velocity (whsv) of between 0.25 h⁻¹ and 1.5h⁻¹.
 50. A process as claimed in claim 49 wherein the process is carriedout with a weight hourly space velocity (whsv) of between 0.56 h⁻¹ and 1h⁻¹.
 51. A process as claimed in any one of claims 38 to 50 wherein thehydrocarbon feed is predominantly a wax feed.
 52. A process as claimedin any one of claims 38 to 51 wherein the hydrocarbon feed is aFischer-Tropsch wax.
 53. A process as claimed in claim 30 wherein theFischer-Tropsch wax is selected from a group including: a primary FTreactor product; wax A, or distillation fractions thereof; wax B; wax Cwherein waxes A, B and C have characteristics as set out in the tablebelow. Wax Characteristics: Wax Type Congealing point (° C.) Substantialcarbon distribution A  83-103  C₅-C₁₂₀ B 49-69 C₁₇-C₄₅ C 71-91 C₃₀-C₈₅


54. A process as claimed in claim 53 wherein the Fischer-Tropsch wax isselected from a group including: a primary FT reactor product; wax A, ordistillation fractions thereof; wax B; wax C wherein waxes A, B and Chave characteristics as set out in the table below. Wax Characteristics:Wax Type Congealing point (° C.) Substantial carbon distribution A 93 C₅-C₁₂₀ B 59 C₁₇-C₄₅ C 81 C₃₀-C₈₅


55. A process for conversion of at least a portion of a hydrocarbon feedhaving a component above the diesel boiling range to diesel,substantially as hereinbefore described or exemplified.
 56. A newprocess substantially as herein described.
 57. An amorphoushydrocracking catalyst according to the invention, as hereinbeforegenerally described.
 58. An amorphous hydrocracking catalyst includingany new and inventive integer or combination of integers, substantiallyas herein described.